Electric regulator of the carbon pile type



Nov. 22, 1949 c, v, usT 2,489,071

ELECTRIC REGULATOR OF THE CARBON PILE TYPE Filed Dec. 19, 1945 2 Sheets-Sheet 1 H l. M 11 m 1| 15 19 g 2 I) 16 Nova 22 1 949 c. v. AUSTIN ELECTRIC REGULATOR OF THE CARBON FILE TYPE 2 sheets sheet 2 Filed Dec. 19, 1945 mmw N Patented Nov. 22, 1949 ELECTRIC REGULATOR OF THE CARBON PILE TYPE Charles Valentine Austin, Eltham, England, assignor to J. Stone & Company Limited, Deptford, England, a British joint-stock company Application December 19, 1945, Serial No. 636,037 In Great Britain December 11, 1944 11 Claims.

This invention of improvements relating to electric regulators of the carbon pile type has for its principal object to provide improved means for the avoidance of oxidation and consequent disintegration of pile elements when these are operated in air at high temperatures. It has already been proposed that a gas-tight enclosure for part of a carbon-pile regulator should contain a gas which will not support combustion. By this means, not only is the pile protected, but a higher pile loading is permissible than would be the case with similar piles operated in air, and high overloads of short duration are not injurious, whereas with piles operated in air such overloads may seriously reduce the useful life of a pile. According to the invention, in an electromagnetic carbon pile regulator, the pile and part of the magnet system of the regulator are surrounded by an inert gas contained in an enclosure, the said pile and part of the magnet system surrounded by the inert gas being enclosed in separate compartments havin restricted flow-cornmunication with each other. The enclosure may be constituted by two casings attached to opposite faces of a partition plate, movement being transmitted from the armature of the magnet system to the movable end of the pile by a strut working through a clearance hole in the plate. The inert gas may be carbon dioxide, nitrogen, hydrogen or other gases which will not support combustion.

Advantageously, the inert gas is contained in the enclosure at a pressure above atmospheric pressure. Any slow leakage is then outwardly and better cooling of the carbon pile can be achieved. Moreover, if the regulator has a dashpot also arranged Within the enclosure, not only is a better dash-pot action obtainable, but, if the dashpot has a rubber diaphragm, it also will be protected against oxidation. Provision may be made for re-setting or adjusting the pile without unsealing or completely unsealing the enclosure and indicating means visible from outside the enclosure may be arranged to show the state of such setting.

If, according to an alternative arrangement, the pile alone is enclosed, it may be arranged in an enclosure, preferably of bellows-like construction, which is compressible and extensible during compression and relaxation of the pile. Preferably, the enclosure is arranged so that When one part thereof is compressed another part is expanded, so that the gas pressure in the enclo sure is not affected during compression and relaxation of the pile and so that, also, relative changes in pressure between the inside and outside of the enclosure do not afiect the compression of the pile.

For this purpose, the enclosure may comprise two cylindrical metal bellows enclosing respective half lengths of the pile, a rigid connection, for example a core rod or cage for the pile, being provided between the opposite ends of the enclosure and one end being engaged with the mov able end of the pile whilst the other end is free to move from and towards the fixed end of the pile. The bellows may be attached to opposite faces of a mounting plate through a hole in which the pile passes, the abutment for the fixed end of the pile being supported by a bridle device from the said plate.

Various ways of carrying the invention into effeet will now be more fully described by Way of example and with reference to the accompanying drawings, in which- Fig. 1 is a plan view of a regulator in which the carbon pile is disposed inside a gas-tight en closure,

Fig. 2 is a longitudinal section of the enclosure to a larger scale,

Fig. 3 a sectional plan view of a regulator which is wholly contained in an enclosure,

Fig. 4 is a perspective detail view of the guide means for the movable collector of the carbon pile in the regulator of Fig. 3, and

'Fig. 5 a sectional view of a modification.

In the regulator construction illustrated in Figs. 1 and 2, a mounting plate I is formed with a hole 2 permitting of the free passage of a pile S and an insulating cage 4 freely guiding the pile. On one side of the plate I, there is attached a cylindrical metal bellows-chamber 5 having one end open and the other end closed. The open end of this chamber is gas-tightly fastened around the hole 2 on the said side. Afiixed to the plate I and extending Within the chamber 5 is a bridle device 6 adapted for presenting a fixed abutment I for engagement by the fixed end of the pile 3 which is provided with a collector disc 8. When the pile has been inserted in the chamber 5, which receives about one half of its length, a similar metal bellows chamber 9 is applied to enclose the other half of the pile and the open end of this chamber is gas-tightly fastened around the hole 2 on the other side of the plate l. The closed end wall of the chamber 9 is adapted for transmitting pressure to the collector disc Hi at the movable end of the pile. An insulated rod M, passing freely through the annular carbon-pile elements, is connected with the aid of end plates l2 rigidly and gas tightly to the end walls of the chambers. This rod ll thus constitutes a rigid connection, movable in relation to the pile, between the opposite ends of the enclosure, i. end of the chamber 9 which is engaged wi movable collector l and the end of the char which is free to move from or towards the fixed collector 8. Leads to the collector discs 3, are brought in through gas-tight bushings 5 In the case of such a small enclosure, it may not be necessary to exh net or displace the air and charge with inert gas bei ore on". The small amount of oxygen will soon be exhausted without any harm being done to the pile. Or the oxygen in such air may be caused to go into combination so as to leave an inert atmosphere, mainly of nitrogen, by iting a small charge of, for example, magnesium in known manner by electrical means. Or the enclosure may charged with air under pressure by means a hand pump, the init pressure be 1g selected so that the ultimate pressure when the atmosphere has been rendered inert is slightly above normal atmospheric pressure. A pressure in of atmospheric has the advantage that any slight outward leakage of gas in the course of time less harmful than an inward leakage of air.

When, in the source of operation of a rogulator embodying an enclosed pile 3, pressure is applied to the movable end l0 oi the pile for varying its resistance, the chamber 9 will be compressed and contracted in length. However. due to the rigid connection established by the rod 1 I, the other chamber 5 will be equally expanded and elongated. Thus the internal pressure within the enclosure 5, 9 remains substantially affected by the compression of the pile. Furthermore, relative changes of pressure either outside or inside the bellows are without effect upon the pile compression.

In an alternative arrangement which may be employed, the pile cage 4 has its ends fixedly connected to the end walls of both chambers 9 and is movable in relation to the pile The cage may then take the place of the rod 1 l which may be dispensed with.

In any case, the cage 4 is preferably not tubular, but consists of several spaced rods to permit of free radiation of heat from the carbon elements to the metal bellows 5, El as well as heattransfer by convection currents within the latter. As the bellows present an extensive corrug ed surface area to the outside air, a very effec -ve cooling effect is attainable. In this connection, it may be added, that a pressure above atmospheric will also assist cooling of the pile due to the greater mass of present.

Other means, for example heat-radiating fins, may be provided for assisting in the transfer of heat from the pile to the enclosure. Also the core rod I I could be made of copper or other good heat conductor with an electrically insulating sheath. the rod being beyond one or both ends of the bellows 5, 9 and furnished there with cooling fins after the fashion described in the specification of U. Patent No. 2,3l4l/il6.

An enclosed pile ent such has been described may be mounted in regulator in readily replaceable manner by attaching its pl...te l to a bracket 13 supported, as illustrated in 1, from the magnet M of the regulator. The pile, disposed horizontally, should located or above the magnet system...

ne regulator may, with advantage, be of the kind in which the poles of the magnet system present two parallel air co-acting with an armature i5 formed with blade-like parts for entering the polar gaps. The armature is carried, like a clapper armature, by one arm of a lever l5 anti-frictionally pivoted on the bracket it by means of intersecting blade springs il. A regulator of this kind is more fully described in the specification of U. S. Patent No. 2,374,417. The other arm of the lever Iii is acted upon by the regulator spring which is not seen as it lies behind the pile arrangement. The said other arm oi the lever is also fitted with an adjustable abutment screw l8 engaging the end wall of the bellows chamber 9 which applies pressure to the movable end of the pile 3. Preferably the lever it is also connected by a rod I!) with a dash pot Bil supported from the bracket IS. The dash pot may be sealed off with bellows devices after the manner described in the specification of U. S. patent application 548,912 and may, if desired, be filled with an inert gas. Finally the lever may further be fitted with a pointer 22 for facilitating accurate resetting of the regulator in known manner. The fixed bracket i3 is provided with a mark 23 indicating the correct setting or with marks or a scale indicating permissible limits of adjustment. A linkage may be introduced for multiplying the movement of the pointer. If desired, the bellows chamber 5 enclosing the fixed end of the pile 3 may be steadied by means of a cantilever blade spring 24 attached to the bracket l3 and bearing against the end wall of the chamber.

A regulator arrangement such as has been described permits of the pile being Worked at a fairly high temperature, not only without harm to itself, but also without serious increase of the temperature being passed on to the regulator winding M where it is liable to impair insulation and render temperature compensation more diflicult. In fact it is possible to work the pile at a comparatively high temperature sufficient for the attainment of effective radiation from the pile 3 to the bellows 5, 9 which provide an efficient dissipating surface as indicated above. Further advantages of this arrangement are the ease with which the enclosed pile unit can be replaced and the possibility of carrying out resetting without breaking any seal.

In the embodiment of the invention illustrated in Figs. 3 and 4, the whole regulator is contained inside an enclosure comprising compartments which are formed by metal casings 26, 21 secured on either side of a plate 28 by screws 29, gastightness being attained by packing means 30. The casing 25, which is closed by a cover 3| s cured by screws 32 and furnished with a packing contains the carbon pile 3. The casing 21 contains the magnet system, indicated generally at the dash-pot 20 whereof the rod I9 is connected to the clapper lever l6, and the regulator spring 315 connected to the said lever by an arm The magnet system may be of the kind described in the first example, the lever it being similarly mounted by means of intersecting blade springs ill. The pile 3 is actuated from the lever by means of a strut 38 which passes through a bare clearance hole 39 in the plate 28 and which has pointed ends engaging recesses in the lever l6 and the movable collector [0 of the pile. This collector is suspended by means of frame-shaped springs lei, ll or diaphragm springs by which it is constrained to move rectilinearly in the direction of the axis of the pile and apply pressure squarely to it. The lower parts of the springs 40,

M are supported by arms 42 of a bracket 43 carried by an insulating base part 44 which is secured to a flange 45 at the end of the casing 26. The upper parts of the springs are connected together by links 46. The collector II] is suspended in a plate 4'! connected by way of the upper part of the spring 40 to the links 46. Electrical connections to the fixed and movable collectors 8, ID are brought in through gas-tight bushings 48. Similar bushings (not seen) serve for the connections to the regulator winding M The whole of the enclosure 26, 21 is to contain an inert atmosphere and any of the methods described with reference to Figs. 1 and 2 may be employed. The casing 26 is shown provided with a spigot 52 having a non-return valve 53. By means of this spigot, air may be exhausted from the sealed enclosure (the valve being held off its seating by a projection on the exhausting connection) and an inert gas then introduced under pressure. For ensuring permanent gas tightness, a cover 54 may be placed over the spigot and sealed off by soldering.

The filling of the enclosure with an inert atmosphere has, as far as the pile is concerned, the same advantages as were set forth in connection with the first example. The enclosure of the dash pot in an inert atmosphere ensures that the diaphragm, commonly made of rubber, is protected against the surface oxidation to which it is liable at elevated temperatures. Moreover, if the inert atmosphere is at a pressure above atmospheric pressure, a larger buffering effect can be obtained from a dash pot of given size than is obtainable in free air. The plate 28 prevents free circulation of gas between the pile compartment and the magnet compartment, so that the high working temperature of the pile 3 will not cause the temperature of the magnet system, particularly the winding I4 to be unduly raised. To

facilitate dissipation of heat from the pile com partment, its casing 25 is provided with cooling fins 50.

The fixed collector 8 is made adjustable, by means of a screw device mounted in the base part 44, for the purpose of setting the regulator and for taking up pile wear from time to time. For the latter purpose, it will be necessary to remove the cover 3|. The fit of the base part 44 is such that the enclosure is not thereby completely unsealed and little air should enter, provided that the cover is not left oft for long. How ever, it may be preferred to recharge with inert gas after such adjustment. Recharging will also be necessary after unsealing of the enclosure for inspection or repair of the regulator. Such recharging may be simply done from a container of gas under pressure through the spigot 52. If desired a gauge communicating with the enclosure by way of a non-return valve may be provided on one of the casings 26, 21 for indicating the pressure in the enclosure.

If preferred, provisions may be made as illustrated in Fig. 5, for adjusting the pile without removing the cover 3! or endangering the sealing of the enclosure. An adjusting rod 55 which passes freely through the cover 3| is supported by a flexible bellows or diaphragm 56 attached to the said cover. The rod can be adjusted and secured by means of nuts El on each side of a bracket 58 which is attached to the cover 3|. Alternatively two diaphragms arranged to give a pressure-compensation effect may be provided. Warning that resetting of the pile is necessary may be provided, as in Fig. 1, by a pointer connected to some part of the clapper lever l6 and visible through a window in the casing 26.

An alternative magnet system which may suitably be employed in regulators according to the invention comprises a U-shaped yoke with a coil on each limb and an armature with a single wedge-shaped tongue operating in a tapering gap at the open end of the U-shaped yoke.

The casing 27 enclosing the magnet system 35 is advantageously made of iron or other magnetic material if it is desired to localise stray magnetic field and prevent interference with other apparatus, for example the compass of an aircraft.

I claim:

1. Electromagnetic regulator of the type comprising an electromagnet and a carbon pile acted upon by the said electromagnet, wherein the carbon pile is disposed in a flexible enclosure which is compressible and extensible during compression and relaxation of the pile under the action of the electromagnet.

2. Electromagnetic regulator of the type comprising an electromagnet and a carbon pile acted upon by the said electromagnet, wherein the pile is disposed in an enclosure of bellows-like construction which contains an inert gas and is compressible and extensible during compression and relaxation of the pile under the action of the electromagnet in such manner that when one part thereof is compressed another part is ex panded, so that the gas pressure in the enclosure is not affected during compression and relaxation of the pile and so that, also, relative changes in pressure between the inside and outside of the enlclosure do not affect the compression of the p1 e.

3. Electric regulator comprising a carbon pile and an enclosure consisting of two cylindrical metal bellows enclosing respective lengths of the pile, a rigid connection being provided between the opposite ends of the enclosure and one end being engaged with the movable end of the pile whilst the other end is free to move from and towards the fixed end of the pile.

4. Electric regulator comprising a carbon pile and an enclosure consisting of two cylindrical metal bellows enclosing respective lengths of the pile, a rigid connection in the form of a core rod for the pile being provided between the opposite ends of the enclosure and one end being engaged with the movable end of the pile whilst the other end is free to move from and towards the fixed end of the pile, the bellows being attached to opposite faces of a mounting plate through a hole in which the pile passes and the abutment for the fixed end of the pile being supported by a bridle device from the said plate.

5. Electromagnetic carbon-pile regulator comprising a carbon pile acted upon at one end by a magnet system, an enclosure containing an inert gas, in which the pile is disposed, and an indicating member mechanically linked with the end of the pile acted upon by the magnet system and visible from outside the enclosure for showing the condition of the setting of the pile.

6. Electromagnetic c a r b o n p 11 e regulator, wherein the pile and part at least of the magnet system of the regulator are surrounded by an inert gas contained in an enclosure, the said pile and part of the magnet system surrounded by the inert gas being enclosed in separate compartments having restricted flow-communication with each other.

'7. Regulator according to claim 6, wherein the enclosure is constituted by two casings attached to opposite faces of a partition plate, movement being transmitted from the armature of the magnet system to the movable end of the pile by a strut working through a clearance hole in the plate.

8. Regulator according to claim 6, wherein the movable end of the pile is guided, independently of the means for transmitting movement from the armature, to move axially of the pile by a parallel-motion spring arrangement.

9. Electro-magnetic carbon-pile regulator comprising a magnet system with an armature arranged to turn about a pivot, a member arranged for transmitting pressure from the said armature to the pile, an enclosure with an inert fluid filling in which the said magnet system and pile are contained, and separating means through which the said pressure-transmitting member is passed without affording free flow-communication between the said pile and magnet system.

10. Electric regulator comprising a carbon-pile, an electromagnet with a pivoted armature system and a compartmented sealed enclosure within separate compartments of which the said pile and magnet are contained, the said compartments having restricted thermal communication and the armature system being operatively engaged with one end of the pile by a strut extending from the magnet compartment to the pile compartment.

11. Electric regulator according to claim 10 and comprising, at the end of the pile engaged by the strut, an end member between the said strut and pile and an arrangement of spaced parallel springs by which the said member is supported and by which it is restricted to a rectilinear movement axially of the pile.

CHARLES VALENTINE AUSTIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,094,121 Cheney Apr. 21, 1914 1,320,994 Turbayne Nov. 4, 1919 1,934,548 Kellogg Nov. 7, 1933 1,953,819 Payne Apr. 3, 1934 2,384,786 Austin Sept. 18, 1945 2,393,952 Austin Feb. 5, 1945 2,399,129 Malone Apr. 23, 1946 

